Graphic recorder.



O. B. THWING.

GRAPHIC RECORDER.

APPLICATION FILED AUG. 24, 1912 1,085,51 1 Patented Jan. 27, 1914.

2 SHBETSSHEET l.

WITNESSES INVENTOR I Allorney F1 i G. B. TH WING.

GRAPHIC RECORDER.

APPLICATION FILED AUG. 24, 1912.

1,085,51 1. Patented Jan. 27, 1914.

2 SHEETS-SHEET 2.

Ji iffy. 6. 7 1

WITNESSES INVENTOR Allorney UNITED STATES OFFICE.

CHARLES B. THWING, OF PHILADELPHIA. PENNSYLVANIA. ASSIGNOR TO THWINGINSTRUMENT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION 0FPENNSYLVANIA.

GRAPHIC RECORDER.

Patented Jan. 27, .1 914.

Original annlication file! August 27, 1911, Serial No. 646,276. Dividedand this application filed August 24, 1912. Serial No. 716,823.

To all UJIIOIIL it may} concern:

Be it known that I, CHARLES B. Trrwino, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented a certain new and useful Improvement inGraphic Recorders, of which the following is a spe ification.

This application is a division of an application filed by me August27th, 1911, Serial Number 616,276, on which Patent No. 141461380, wasgranted December 10, 1912.

My invention relates to an improvement in graphic recorders, and itconsists in a recorder which will facilitate the making on a singlerecord sheet or chart of a plurality of records in frequent successionfrom a plurality of sources, these records being repeated so as to giveessentially a continuous record of all the sources of energy. Forexample, if it be desired to record on a single chart the electriccurrent consumed on a plurality of circuits, the several circuits willbe automatically switched into the recorder in regular succession, myimprovement providing a simple and practical method of making visible onthe record chart which portions of the record thereon were made thecurrent from each of the several electric circuits. In similar manner anumber of pipes carrying fluids under pressure could be automaticallyand suc- -cessively thrown into connection with a recording pressuregage.

The essential features of an instrument which is to give a graphicrecord of the variation of any measured quantity with the time consistsof a registering element and a surface which receives the record made bythe registering element, the latter of which moves in a given directionwith the lapse of time, the former remaining in operative recordingcontact with the recording surface varyin lengths of time accordingly asone or 111105161 source of energy is turned into the recorder. In suchrecordin instruments, the receiving element, calle hereinafter thechart, moves over equal intervals in equal'times, sometimes continuouslyand sometimes by short steps with intervening intervals of rest. Therecording element, hereinafter called the pen, may be depressed orotherwise caused to record on the chart at intervals, or it may becaused to remain continuously in contact with the chart. My presentinvention relates to the latter form in which the recording instrumentis constantly held in recording engagement with the chart.

I shall now describe my invention so that others skilled in the arttowhich it appertams may manufacture and use the same, reference being hadto the. accompanying drawings, forming part of this specification, inwhich Figure 1 is a top plan View of a recorder embodying my invention.Fig. 2 is a side elevation of the same omitting the clockwork casing forthe sake of clearness. Figs. 3 and 3, and 4, and5 and 5, are enlargeddetail views of the pawl and ratchet mechanism shown in Figs. 1 and 2which I employ to effect the movement of the chart. Fig. 6 is a portionof a chart showing a record such as would be made by the recorder.

Like symbols of reference indicate like parts in the several figures.

In the drawings, 2 indicates the needle or pen of any ordinary form ofgalvanometer 3, which needle or pen when the instrument is in use iskept in recording contact with the chart 4 by the yoke 3*, but is freeto mom from side to side of the chart in accordance with thefluctuations of the current actuating the galvanometer. The chart tisheld against the drum 5 and compelled to travel therewith by twoconnterhalancing weights 4'. The drum 5 is mounted on a shaft 6, on theouter end of which is a ratchet wheel '7 of peculiar design having teetha, 7), 0. unequally spaced, illustrated in detail in Figs. 3 to 5.Mounted on a disk 8, is a pawl 9.

engaging and adapted to move the ratchet wheel, and thus to rotate thedrum The disk 8 is fixed on a shaft 10, which in turn is mounted in abracket 11 extending from the casing 12 of a clock-work mechanism. Awheel 13 of the clock-work mechanism is adapted to engage a wheel 14 onthe shaft 10 of the disk 8, and thus to rotate or move said diskconstantly at any desired or predetermined speed. While the movement ofthe pawl disk 8 is always constant, the movement of the ratchet wheel 7actuated by the pawl 9 is not constant but irregular, due to itsunequally spaced teeth a, b, 0. By referring to Figs. 3 and 3, it willbe seen that the distance moved forward by the ratchet wheel is nearlyequal to the full length of the stroke of the pawl, while in Figs. 4and/ il the pawl movcsridly for about twothirds of its 'l'orward strokeand moves the drum 5 for about. one-third of its stroke. in Figs. 5 and5 the pawl moves idly for about onethird of its forward stroke andeffectively for about two-thirds. In this mannerthe -)awl mechanismmoving at a constant speed causes the paper on the drum 5, which isactuated by the ratchet wheel 7, to traverse unequal distances in equaltimes.

The operation of my improved recorder is as follows: The sources ofenergy, in this particular Fig. 1 as A, B', C; The recorder is soconstructed that the relative movements of the -pen and chart during thetime the difiterent sources of energy, A, B, C, are recording shall besuch that the length of the element made by source A shall be differentfrom the graph B made by the source B, and the length of the graph Gmade by source C shall be different from both A and B Thus if it isdesired to make three records, distinguishable from each other, of thecurrent in circuits A, B, C, the three circuits will be successivelythrown into circuit with the galvanometer by an automatic switch 15,having three stationary or graph A contacts A, B, C, connectedrespectively with the sources of energy A, B, C. Over these contacts A,B, C, travels a movable contact-16 in the galvanometer circuit. Themovable contact l6'travels over the contacts A, B, I, at a constantspeed, being actuated by the wheel 17 which in turn is moved by thewheel 13 of the clock-work; The construction of the switch 15 and themovable contact 16 is such that the passage of such contact from onestationary contact A, B,

. or CI, to another is instantaneous, prevent ing the needle of thegalvanometer from returning to zero. The pen 2 of the galvanometer 3being continuously onthe chart, the

records of the three sources will be made, but due to the irregularmovement of the chart caused by the ratchet wheel 7 the records orgraphs will-take the form illustrated in Fig. (3, where A is shown asmaking the shortest graph A, B a longer one B, and C the longest Byconnecting the ends of the case electrical, are designated in graphs Atogether by dotted lines, the graph would be complete. The same is truealso of the graphs B and C.

The mechanical or automatic means employed in the construction justdescribed for throwing the several sources of energy successively intoconnection with the recorder may be varied at'pleasure, as may also themeans used to vary the distance moved by thechart during any giveninterval of time.

It will be understood that various changes may be made in the mechanicaldetails of my iniproved recorder without sacrificing any of itsadvantages or departing from the spirit of the invention.

The advantages of my improvement will be readily apparent-to thoseskilled in the art. My improved recorder is simple in construction,compact, and very reliable in operation.

I claim 1. In an automatic multiple recorder, the combination of achart, means for moving said chart varying distances in equal periods oftime, and a recording instrument responding to a plurality of sources ofenergy and adapted to make a record on said chart at each of themovements of the chart:

2. I n an automatic multiple recorder, the combination of a chart, meansfor moving said chart varying distances in equal periods of time, agalvanometer adapted to be connected to and to respond to a plurality ofelectrical currents and to make a record on said chart'at each of themovements of the chart, and means for automatically throwing saidgalvanometer into circuit with said electrical circuits.

3. In an automatic multiple recorder, the combination ofa chart, meansfor moving said chart varying distances in equal periods of time, and arecording instrument held con- 'stantly against the chart when therecorder is in'operation and responding toa plurality of sources ofenergy and adapted to make a record on said chart at each of themovements of the chart.

In testimony whereof I have hereunto set my hand.

CHARLES B. THWING.

Witnesses:

-CHAS. SANDER, D. C. DRAPER.

